JP4407736B2 - Developing device and process cartridge - Google Patents

Description

  The present invention relates to a developing device and a process cartridge.

  2. Description of the Related Art Conventionally, there are known a developing device that has a toner accommodating portion that accommodates toner supplied to a developing roller and has a replenishing port formed at the upper portion thereof, and a toner cartridge that is detachably mounted above the toner accommodating portion. (For example, refer to Patent Document 1). In such a developing device, the toner accommodated inside the toner cartridge is supplied to the toner accommodating portion by dropping into the toner accommodating portion via the replenishing port.

JP-A-6-222665 (FIG. 7)

  By the way, in the developing device as described above, the toner supplied to the toner storage unit moves back and forth between the inside and the outside of the toner storage unit near the replenishing port by the stirring member that stirs the toner in the toner storage unit. Therefore, there is a problem that the toner leaks from the gap between the developing device and the toner cartridge. In particular, when the stirring member has a flexible stirring blade that stirs the toner while being in sliding contact with the inner wall of the toner storage portion, the stirring blade is in sliding contact with the vicinity of the tip being bent, and the bending is recovered at the supply port. In this case, the toner in front of the stirring blade in the rotating direction is moved toward the outside.

  SUMMARY An advantage of some aspects of the invention is that it provides a developing device and a process cartridge that suppress leakage of developer from a developer container.

In order to achieve the above-described object, a developing device of the present invention includes a developing roller, a developer containing portion that contains a developer supplied to the developing roller, and has a replenishing port formed in the upper portion thereof, and the developer An agitating member provided in the accommodating portion and having a rotating base and a flexible agitating blade fixed to the base and agitating the developer while being in sliding contact with the sliding portion of the developer accommodating portion; The upstream end of the replenishing port in the rotation direction of the stirring member is located at the front end in the rotation direction of the stirring member at the base end of the stirring blade when the free end of the stirring blade comes to the end. The surface of the developer accommodating portion is formed at a position where the surface is inclined vertically or downward, and the sliding portion of the developer accommodating portion is located at a position of the stirring member of the replenishing port from a portion overlapping the projection of the rotation center of the stirring member vertically upward. To the upstream end in the direction of rotation Wherein the inclined to Unishitagatte downward.

  According to the developing device configured as described above, before the flexure of the free end of the stirring blade is recovered and extended at the replenishing port, the development placed on the stirring blade, that is, on the front surface in the rotation direction of the stirring blade. The agent can be dropped. Accordingly, the toner can be prevented from moving toward the outside, so that the developer can be prevented from going back and forth between the inside and the outside of the developer accommodating portion in the vicinity of the replenishing port.

  Further, the present invention can be configured as a process cartridge including the developing device and a photosensitive member on which an electrostatic latent image is formed and a developer is supplied from the developing device to form a developer image. .

  According to the present invention, since the flow of the developer between the inside and the outside of the developer accommodating portion in the vicinity of the replenishing port can be suppressed, the leakage of the developer from the developer accommodating portion can be suppressed. It becomes.

Next, embodiments of the present invention will be described in detail with reference to the drawings as appropriate. In the drawings to be referred to, FIG. 1 is a cross-sectional view showing the overall configuration of a laser printer as an example of an image forming apparatus, and FIG. 2 is a cross-sectional view showing the configuration of a process cartridge.
Here, in the following description, the direction will be described with reference to the user when using the laser printer and mounting the process cartridge. That is, in FIGS. 1 and 2, the right side toward the paper surface is the “front side”, the left side toward the paper surface is the “back side”, the back side toward the paper surface is the “right side”, and the near side toward the paper surface is the front side. “Left side”. In addition, the vertical direction toward the page is defined as the “vertical direction”.

<Overall configuration of laser printer>
As shown in FIG. 1, the laser printer 1 forms a toner image (developer image) on the paper feed unit 3 for feeding the paper P into the main body housing 2, the exposure device 4, and the paper P. And a fixing device 8 for fixing the toner image formed on the paper P.
A front cover 2A that can be freely opened and closed is provided on the front side of the main body housing 2, and the process cartridge 5 is detachable from an opening formed when the front cover 2A is opened (not shown).

<Configuration of paper feed unit>
The paper feed unit 3 includes a paper feed tray 31 that is detachably attached to the lower part of the main body housing 2, a paper pressing plate 32 that is swingably provided on the lower front side of the paper feed tray 31, and a paper A lift lever 33 is provided for lifting the pressing plate 32 from below. A paper feed roller 34, a paper feed pad 35, and a pinch roller 36 are provided above the front side of the paper feed tray 31, and a registration roller 37 is provided behind the paper feed roller 34. The paper P in the paper feed tray 31 is brought close to the paper feed roller 34 by the lift lever 33 and the paper pressing plate 32, sent out by the paper feed roller 34 and the paper feed pad 35, and passes through various rollers 34, 36, 37. After that, they are conveyed one by one to the process cartridge 5.

<Configuration of exposure apparatus>
The exposure apparatus 4 is provided in the upper part of the main body housing 2 and mainly includes a laser light emitting unit (not shown), a polygon mirror 41 that is rotationally driven, lenses 42 and 43, and reflecting mirrors 44 and 45. I have. The laser beam based on the image data emitted from the laser emission unit is reflected or passed through the polygon mirror 41, the lens 42, the reflecting mirror 44, the lens 43, and the reflecting mirror 45 in this order, as indicated by a chain line, and the process cartridge 5 The surface of the photosensitive drum 52 is irradiated with high-speed scanning.

<Configuration of process cartridge>
The process cartridge 5 is provided below the exposure apparatus 4 and has a structure that is detachably attached to the main body housing 2. As shown in FIG. 2, the process cartridge 5 includes a photosensitive drum 52 as an example of a photosensitive member, a scorotron charger 53, a transfer roller 54, and a developing device in a hollow cartridge frame 51 constituting an outer frame. 6 is provided. A toner cartridge 7 as an example of a developer cartridge is detachably mounted on the process cartridge 5 (developing device 6).

  The photosensitive drum 52 is rotatably supported by the cartridge frame 51. The photosensitive drum 52 has a drum body grounded and a surface portion formed of a positively chargeable photosensitive layer.

The scorotron charger 53 is disposed above the photosensitive drum 52 so as to be opposed to the photosensitive drum 52 with a predetermined interval, and is configured to uniformly charge the surface of the photosensitive drum 52 to a positive polarity.
The transfer roller 54 is disposed so as to face and contact the lower portion of the photosensitive drum 52, and is rotatably supported by the cartridge frame 51. A transfer bias is applied to the transfer roller 54 during transfer.

  The developing device 6 includes a frame 61 that is detachably attached to the cartridge frame 51 and forms an outer frame, a toner accommodating portion 61A as an example of a developer accommodating portion, and a developing portion 61B. The developing device 6 further includes an agitator 62 as an example of a stirring member in the toner accommodating portion 61A, and a developing roller 63, a layer thickness regulating blade 64, and a supply roller 65 in the developing portion 61B. The frame 61 rotatably supports the agitator 62, the developing roller 63, and the supply roller 65.

  The toner cartridge 7 is detachably attached to the frame 61 above the toner accommodating portion 61A of the developing device 6. The toner T as an example of the developer in the toner cartridge 7 is supplied by dropping into the toner accommodating portion 61A by its own weight when the toner cartridge 7 is mounted on the frame 61. The toner T in the toner container 61A is stirred by the rotation of the agitator 62, conveyed into the developing unit 61B, and further supplied to the developing roller 63 by the rotation of the supply roller 65. At this time, the toner T is frictionally charged between the supply roller 65 and the developing roller 63. The toner T supplied onto the developing roller 63 enters between the layer thickness regulating blade 64 and the developing roller 63 by the rotation of the developing roller 63 and is carried on the developing roller 63 as a thin layer having a constant thickness. .

  In the process cartridge 5 configured as described above, the surface of the photosensitive drum 52 is uniformly positively charged by the scorotron charger 53 and then exposed by high-speed scanning of the laser beam from the exposure device 4. Thereby, the potential of the exposed part is lowered, and an electrostatic latent image based on the image data is formed. Next, when the photosensitive drum 52 and the developing roller 63 come into contact with each other due to the rotation of the developing roller 63, the toner T carried on the developing roller 63 is electrostatically formed on the surface of the photosensitive drum 52. Supplied to the latent image. Thus, the toner T is selectively carried on the surface of the photosensitive drum 52, whereby the electrostatic latent image is visualized and a toner image is formed by reversal development. Then, the photosensitive drum 52 and the transfer roller 54 rotate so as to sandwich and convey the paper P between them, and the paper P is conveyed between the photosensitive drum 52 and the transfer roller 54, whereby the photosensitive drum 52. The toner image carried on the surface is transferred onto the paper P.

<Configuration of fixing device>
As shown in FIG. 1, the fixing device 8 is provided on the back side of the process cartridge 5 (downstream in the conveyance direction of the paper P), and is disposed opposite the heating roller 81 and the heating roller 81. A pressure roller 82 that holds the paper P therebetween is provided. A paper discharge path 83 and a paper discharge roller 84 for discharging the paper P to the outside of the main body housing 2 are provided on the downstream side of the fixing device 8 in the conveyance direction of the paper P. The toner image transferred onto the paper P is thermally fixed while the paper P passes between the heating roller 81 and the pressure roller 82. The paper P conveyed from the fixing device 8 to the paper discharge path 83 is discharged onto a paper discharge tray 85 by a paper discharge roller 84.

<Detailed configuration of developing device and toner cartridge>
Next, detailed configurations of the developing device 6 and the toner cartridge 7 will be described.
As described above, the developing device 6 includes the frame 61, the agitator 62, the developing roller 63, the layer thickness regulating blade 64, and the supply roller 65 that form the toner accommodating portion 61A and the developing portion 61B.

As shown in FIG. 2, the frame 61 includes an outer frame (not shown) of the developing device 6, a toner containing portion 61 </ b> A that contains toner T supplied to the developing roller 63, a developing roller 63, and a layer thickness regulating blade 64. And a developing unit 61B in which a supply roller 65 is disposed, and a mounting unit 61C in which a toner cartridge 7 described later is mounted. Such a frame 61 may be formed integrally with each part, or may be configured by individually forming each part and assembling.
In the toner container 61A, a supply port 611 is formed at the top, and an internal supply port 619 that communicates with the developing unit 61B is formed at the back. The formation position of the supply port 611 in this embodiment will be described later.

  The agitator 62 is provided in the toner container 61A, agitates the toner T in the toner container 61A, and conveys the toner T to the developing unit 61B via the internal supply port 619. The agitator 62 includes a rotation support shaft 621, a base 622, and a stirring blade 623.

  The rotation support shaft 621 is a shaft extending in the left-right direction of the toner containing portion 61A, and both ends thereof are rotatably supported on the side wall of the toner containing portion 61A. The agitator 62 rotates in the toner accommodating portion 61 </ b> A by being applied with a driving force from a driving source (not shown) such as a motor provided in the main body housing 2 with respect to the rotation support shaft 621. Stir and transport T.

  The base 622 is a plate-like member fixed along the axial direction of the rotation support shaft 621, and has one end of the stirring blade 623 on the front surface in the rotation direction of the agitator 62 (hereinafter simply referred to as “rotation direction”). The portion (base end portion 623A) is fixed by sticking or the like. Note that the rotation support shaft 621 and the base 622 may be integrally formed.

The stirring blade 623 is a flexible sheet-like member that stirs and conveys the toner T while being in sliding contact with the ribs 614 and 615 and the bottom portion 616 of the toner containing portion 61A, and has one end fixed to the base 622. Yes.
Here, as shown in FIG. 2, the ribs 614 and 615 are provided on the back side of the replenishing port 611 in the upper part of the toner accommodating portion 61A, respectively, extend along the rotational direction of the agitator 62, and are arranged in a plurality in the left-right direction. It is a rib (plate material) arrange | positioned by. Such ribs 614 and 615 are an example of a sliding portion with which the stirring blade 623 slides.

  In the following description, one end portion of the stirring blade 623 fixed to the base portion 622 is referred to as a base end portion 623A, and the rib 614, 615 and the bottom portion 616 of the toner storage portion 61A are on the opposite side of the base end portion 623A. Let the edge part which slidably contact be the free end 623B. When the agitating blade 623 is in sliding contact with the ribs 614, 615 and the bottom 616 of the toner accommodating portion 61A, the free end 623B is bent so as to face the rear in the rotational direction, and the free end 623B is connected to the supply port 611 and the internal supply. When facing the mouth 619, the flexure recovers and extends (see FIG. 3).

Here, the formation position of the supply port 611 in the present embodiment will be described. FIG. 3 is an enlarged cross-sectional view showing the configuration of the developing device.
As shown in FIG. 3, the replenishment port 611 has an upstream end (hereinafter referred to as an upstream end) 612 in the rotation direction, and a free end 623 </ b> B of the stirring blade 623 comes to the upstream end 612 ( 3 is formed at a position where the front surface in the rotation direction of the base end portion 623A is inclined downward.

  More specifically, the replenishing port 611 has an upstream end 612 at the downstream side in the rotational direction from the portion S of the rib 615 of the toner containing portion 61A that overlaps the vertical projection of the rotational center C of the agitator 62. That is, it is formed on the front side of the part S. Further, the surface G of the rib 615 of the toner containing portion 61 </ b> A is inclined downward from the portion S toward the upstream end 612 of the supply port 611.

  As shown in FIG. 3, the toner cartridge 7 is detachably mounted on the mounting portion 61 </ b> C of the frame 61 above the toner accommodating portion 61 </ b> A of the developing device 6, and the frame 71 is formed in a cylindrical shape. The shutter 72 is mainly provided.

  A supply port 711 that communicates with the replenishment port 611 is formed below the frame 71 when the developing device 6 is mounted. Further, the accommodation volume of the toner T of the toner cartridge 7 formed by the frame 71 is smaller than the accommodation volume of the toner T in the toner accommodation portion 61A.

  As shown in FIG. 2, the shutter 72 closes the supply port 711 when the toner cartridge 7 is detached from the developing device 6. The frame 61 of the developing device 6 is also provided with a shutter 61D that closes the supply port 611 when the toner cartridge 7 is removed. When the toner cartridge 7 is mounted on the developing device 6, the shutter 61 </ b> D and the shutter 72 are rotated manually or electrically by a known configuration to connect the supply port 611 and the supply port 711.

  In the present embodiment, as shown in FIG. 3, a surface F (FIG. 3) connecting a lower end 613 of the upstream end 612 of the supply port 611 and a lower end 712 on the downstream side in the rotation direction of the supply port 711. 3) is configured to come above the free end 623 </ b> B of the stirring blade 623 that has fully recovered its flexure.

Next, the operation of the developing device 6 according to this embodiment will be described while explaining the operation of the agitator 62. 4A to 4D are views for explaining the operation of the agitator.
When the agitator 62 rotates, the free end 623B of the stirring blade 623 enters the toner T accumulated in the bottom 616 of the toner containing portion 61A. As shown in FIG. 4A, the free end 623B of the stirring blade 623 conveys the toner T to the developing unit 61B while slidingly contacting the bottom 616 of the toner containing unit 61A.

  Although not shown, when the amount of toner T in the toner containing portion 61A is small, the free end 623B of the stirring blade 623 slides against the bottom 616 of the toner containing portion 61A and the little toner T collected on the bottom 616. The toner T is vigorously conveyed to the developing portion 61B by recovering the bending and reaching the bottom when reaching the lower end of the internal supply port 619.

  As shown in FIG. 4B, the toner T remains on the front surface in the rotational direction of the stirring blade 623 even after the agitator 62 rotates and the bending of the stirring blade 623 recovers and extends. As shown in FIG. 4C, the agitator 62 rotates and the free end 623B of the stirring blade 623 comes into sliding contact with the ribs 614 and 615 of the toner containing portion 61A from the upper end of the internal supply port 619, and the base end portion 623A When the front surface in the rotation direction approaches vertical, the toner T remaining on the front surface in the rotation direction of the stirring blade 623 falls toward the bottom 616 of the toner storage portion 61A.

  In the developing device 6 according to this embodiment, since the supply port 611 is formed at the above-described position, the upstream end 612 of the supply port 611 is rotated as the agitator 62 rotates as shown in FIG. When the free end 623B of the stirring blade 623 comes, the front surface in the rotation direction of the base end portion 623A is completely inclined downward, so that the toner T remaining on the front surface in the rotation direction of the stirring blade 623 is Almost everything has fallen.

  Here, in general, the toner T in front in the rotation direction of the stirring blade moves in a direction in which the front surface in the rotation direction of the stirring blade which has recovered its deflection at the replenishing port is directed. In the developing device 6 according to this embodiment, as shown in FIG. 3, the front surface in the rotational direction of the stirring blade 623 that has recovered its deflection at the replenishing port 611 and extends is directed to the arrow X direction. The toner T that has not dropped from the front surface in the rotational direction of the blade 623 flies in the direction of the arrow X when the stirring blade 623 has recovered its deflection at the supply port 611 and has fully extended. Therefore, the toner T does not fly outside the toner accommodating portion 61A or in the gap between the mounting portion 61C and the toner cartridge 7.

According to the above, the following effects can be obtained in the present embodiment.
The replenishing port 611 is formed at a position such that when the free end 623B of the stirring blade 623 comes to the upstream end 612, the front surface in the rotation direction of the base end 623A is inclined downward. With such a configuration, before the free end 623B of the stirring blade 623 of the rotating agitator 62 recovers from bending at the upstream end 612 of the replenishing port 611 and extends, the stirring blade 623 rotates on the front surface in the rotation direction. Almost all of the remaining toner T can be dropped. According to this, even when the deflection of the stirring blade 623 recovers and extends, almost no toner T remains on the front surface in the rotational direction of the stirring blade 623, so that the toner T moves toward the outside of the toner container 61A. Flying can be suppressed. Therefore, since the toner T can be prevented from going back and forth between the toner container 61A and the toner cartridge 7 near the replenishing port 611, leakage of the toner T from the toner container 61A can be suppressed.

  The replenishing port 611 has an upstream end 612 formed on the downstream side in the rotational direction with respect to the portion S of the rib 615 of the toner containing portion 61A. With such a configuration, even if the stirring blade 623 recovers the deflection at the replenishing port 611 and extends, the toner T does not fly upward in the horizontal direction. Therefore, the toner T toward the outside of the toner storage portion 61A. Can be prevented from flying. Accordingly, since the toner T can be prevented from going back and forth between the toner container 61A and the toner cartridge 7 near the replenishing port 611, leakage of the toner T from the toner container 61A can be suppressed.

  The surface G of the rib 615 of the toner container 61A is inclined downward from the portion S toward the upstream end 612 of the supply port 611. With such a configuration, even if the stirring blade 623 recovers from the deflection at the supply port 611 and extends, the toner T flies downward (in the direction of the arrow X in FIG. 3), so the outside of the toner container 61A, It is possible to prevent the toner T from flying in the gap between the mounting portion 61C and the toner cartridge 7. Accordingly, since the toner T can be prevented from going back and forth between the toner container 61A and the toner cartridge 7 near the replenishing port 611, leakage of the toner T from the toner container 61A can be suppressed.

  A surface F connecting the supply port 611 (lower end portion 613) and the supply port 711 (lower end portion 712) is configured to be above the free end 623B of the agitated stirring blade 623. With such a configuration, even if the stirring blade 623 recovers from the deflection at the replenishing port 611 and extends, the toner T does not fly above the surface F, so the outside of the toner containing portion 61A or the mounting portion 61C. And the toner cartridge 7 can be prevented from flying in the gap between the toner cartridge 7 and the toner cartridge 7. Accordingly, since the toner T can be prevented from going back and forth between the toner container 61A and the toner cartridge 7 near the replenishing port 611, leakage of the toner T from the toner container 61A can be suppressed.

  Since the accommodation volume of the toner T in the toner cartridge 7 is smaller than the accommodation volume of the toner T in the toner accommodation portion 61 </ b> A, the toner T accommodated in the toner cartridge 7 is almost the same as the toner cartridge 7 is mounted on the developing device 6. The entire amount is supplied to the toner container 61A by dropping through the supply port 711 and the supply port 611. According to this, toner T stays in the vicinity of the replenishing port 611, that is, in the vicinity of the gap between the mounting portion 61C and the toner cartridge 7, so that the toner T is placed in the gap between the mounting portion 61C and the toner cartridge 7. It can suppress entering. Therefore, when the toner cartridge 7 is removed from the developing device 6, it is possible to suppress the leakage of the toner T that has entered the gap between the mounting portion 61 </ b> C and the toner cartridge 7.

  Next, modified examples of the present invention will be described with reference to the drawings as appropriate. In addition, about the component similar to above-described embodiment, the same code | symbol is attached | subjected and the description is abbreviate | omitted. FIG. 5A is a cross-sectional view illustrating the configuration of the developing device according to the first modification, and FIG. 5B is a view taken along the arrow Z in FIG.

  As shown in FIG. 5A, the developing device 6 according to the first modification includes a rotation center C of the agitator 62 from the lower end 613 of the upstream end 612 of the replenishing port 611 to the front side of the toner storage 61A. Is further provided with a guide member 66 provided in a substantially arc shape in side view. As shown in FIG. 5B, the guide member 66 is formed in a wire shape (linear shape) extending in the sliding contact direction (left-right direction in the drawing) of the stirring blade 623, and 4 in the left-right direction of the developing device 6. In addition, since the toner T is provided at an appropriate interval, the toner T can be supplied from the toner cartridge 7 to the toner container 61A. The guide member 66 is formed in a substantially cylindrical shape with a sliding contact surface with which the stirring blade 623 is slidably contacted with the ribs 614 and 615 of the toner accommodating portion 61A.

  By providing such a guide member 66, the agitator 62 can be slidably brought into sliding contact with the ribs 614, 615 and the guide member 66 of the toner containing portion 61A while the inside and outside of the toner containing portion 61A are in communication with each other. Can be rotated. As a result, the stirring blade 623 does not extend by recovering the deflection except for the internal supply port 619, so that the toner T can be completely prevented from being blown by the stirring blade 623 at the supply port 611. Therefore, since the toner T can be prevented from going back and forth between the toner container 61A and the toner cartridge 7 near the replenishing port 611, the leakage of the toner T from the toner container 61A can be further suppressed.

  The guide member 66 formed in a wire shape is an example of the “guide member” recited in the claims, and is not limited to such a configuration. As another example, a plurality of ribs (plate members) along the sliding contact direction of the stirring blade are arranged in the left-right direction, and the sliding contact surface of the stirring blade is formed in a substantially cylindrical shape together with the sliding portion of the developer storage portion. May be adopted. Moreover, the structure which provided the guide member formed in mesh shape along the sliding contact direction of a stirring blade near the replenishment port may be sufficient.

FIG. 6 is a cross-sectional view illustrating a configuration of a developing device according to a second modification.
The replenishing port 611 (see FIG. 3) of the above-described embodiment is an opening formed in the frame 61 (wall surface). However, as shown in FIG. 6, in the developing device 6 according to the second modification, the replenishing port 67 is provided. Is formed in the shape of a passage extending upward from the upper portion of the toner containing portion 61A. The supply port 67 has an upper end opening 671 provided above the free end 623 </ b> B of the stirring blade 623 that has fully recovered its deflection. The lower end 673 of the upstream end 672 of the supply port 67 (the upstream end in the rotational direction of the agitator 62) is the same as the lower end 613 of the upstream end 612 of the supply port 611 of the above-described embodiment. Placed in position.

  By having such a passage-shaped replenishing port 67, the toner T does not fly to the opening 671 at the upper end of the replenishing port 67 even if the stirring blade 623 recovers the deflection at the lower end of the replenishing port 67 and extends. Therefore, it is possible to prevent the toner T from flying outside the toner containing portion 61A or in the gap between the mounting portion 61C and the toner cartridge 7. Accordingly, since the toner T can be prevented from going back and forth between the toner container 61A and the toner cartridge 7 in the vicinity of the opening 671 at the upper end, the leakage of the toner T from the toner container 61A can be further suppressed. .

FIG. 7 is a cross-sectional view illustrating a configuration of a developing device according to a third modification.
As shown in FIG. 7, the developing device 6 according to the third modification includes an agitator 62 ′ having a base 622 ′ in which the shape of the base 622 (see FIG. 2) of the agitator 62 according to the above-described embodiment is changed. . The base 622 ′ is formed with an inclined surface at an end opposite to the rotation support shaft 621 in the front surface in the rotational direction of the agitator 62 ′, and the base end 623A of the stirring blade 623 is fixed to the inclined surface. Has been.

  In the developing device 6 having such an agitator 62 ′, when the agitator 62 ′ rotates and the free end 623B of the stirring blade 623 comes to the upstream end 612 of the replenishing port 611, the rotation direction of the base end 623A The front surface at is vertical. As a result, the toner T remaining on the front surface in the rotation direction of the stirring blade 623 can be dropped before the stirring blade 623 recovers the flexure and extends, which is equivalent to the developing device 6 according to the above-described embodiment. The effect of can be obtained.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to above-described embodiment. About a concrete structure, it can change suitably in the range which does not deviate from the meaning of this invention.

  In the above-described embodiment, an example in which the photosensitive drum 52 is used as an example of the photoconductor, the agitator 62 is used as an example of the stirring member, and the toner T is used as an example of the developer is described. However, the present invention is not limited thereto. The material, structure, etc. can be changed as appropriate without departing from the scope.

  In the above-described embodiment, an example in which the accommodation volume of the toner T in the toner cartridge 7 is smaller than the accommodation volume of the toner T in the toner accommodation portion 61A is shown, but the present invention is not limited to this. For example, the developer storage volume of the developer cartridge is set to be smaller than the sum of the developer storage volume of the developer storage section and the developer storage volume of the development section where the developing roller is provided. May be.

  Even with such a configuration, when the developer cartridge is mounted on the developing device, almost the entire amount of the developer in the developer cartridge is first dropped and supplied to the developer container, and then supplied to the developer. . Therefore, it is possible to eliminate the stay of the developer in the vicinity of the gap between the mounting portions of the developing device and the developer cartridge, so that the developer can be prevented from entering the gap, and the developer cartridge is removed from the developing device. Sometimes leakage of the developer can be suppressed. In addition, when the developer cartridge is installed in the developing device, the developer is supplied to the developing unit and also to the developing roller, so that an image with good image quality can be formed immediately after the developer cartridge is replaced. It becomes.

  The present invention is also applicable to the case where the developer storage volume of the developer cartridge is larger than the combined volume of the developer storage volume in the developer storage section and the developer storage volume in the development section. It is. However, it is more remarkable that the developer storage capacity of the developer cartridge is smaller than the combined volume of the developer storage capacity of the developer storage section and the developer storage capacity of the development section. Can be obtained.

1 is a cross-sectional view illustrating an overall configuration of a laser printer as an example of an image forming apparatus. It is sectional drawing which shows the structure of the process cartridge which concerns on embodiment of this invention. FIG. 2 is an enlarged cross-sectional view illustrating a configuration of a developing device according to an embodiment of the present invention. (A)-(d) is a figure explaining operation | movement of an agitator. (A) is sectional drawing which shows the structure of the image development apparatus concerning the 1st modification of this invention, (b) is a Z arrow directional view of (a). It is sectional drawing which shows the structure of the developing device which concerns on the 2nd modification of this invention. It is sectional drawing which shows the structure of the developing device which concerns on the 3rd modification of this invention.

Explanation of symbols

5 Process Cartridge 6 Developing Device 7 Toner Cartridge 52 Photosensitive Drum 61A Toner Storage Unit 61B Developing Unit 62 Agitator 62 ′ Agitator 63 Developing Roller 66 Guide Member 67 Supply Port 611 Supply Port 612 Upstream End 613 Lower Bottom 614 Rib 622 Base 622 'base 623 stirring blade 623A base end 623B free end 671 opening 672 upstream end 711 supply port 712 lower end C rotation center F surface S part T toner

Claims (9)

A developing roller;
A developer containing portion that contains the developer supplied to the developing roller, and has a replenishing port formed at the top;
An agitation member provided in the developer accommodating portion and having a rotating base, and a flexible agitating blade fixed to the base and agitating the developer while being in sliding contact with the sliding portion of the developer accommodating portion; With
The upstream end of the replenishing port in the rotation direction of the stirring member is located at the front end in the rotation direction of the stirring member at the base end of the stirring blade when the free end of the stirring blade comes to the end. Formed in a position where the surface tilts vertically or downwards ,
The sliding portion of the developer accommodating portion is inclined downwardly from the portion overlapping the projection of the rotation center of the stirring member vertically upward toward the upstream end portion of the supply port in the rotation direction of the stirring member. developing apparatus is characterized in that is.   The upstream end of the replenishing port in the rotation direction of the stirring member has a portion of the stirring member that is overlapped with a portion of the sliding portion of the developer accommodating portion that overlaps the projection of the rotation center of the stirring member vertically upward. The developing device according to claim 1, wherein the developing device is formed on a downstream side in the rotation direction. The replenishing port is formed in a passage shape extending upward from the upper portion of the developer accommodating portion,
The opening in the upper end of the supply port, a developing device according to claim 1 or claim 2, characterized in that above the free end of the stirring blade was stretched. The guide member which forms the sliding contact surface with the said stirring blade with the said sliding part in a substantially cylindrical shape, making the inside and the exterior of the said developer accommodating part communicate. 4. The developing device according to any one of items 3 . The developing device according to claim 4 , wherein the guide member is a linear member formed to extend in a sliding contact direction of the stirring blade. A developer cartridge is configured to be detachable above the developer accommodating portion,
The developer cartridge, accommodating volume of the developer, any one of claims 1 to 5, wherein said developing roller and said developer accommodating portion is less than the volume capacity of the developer in the developing portion provided 2. The developing device according to item 1. The developer cartridge is formed with a supply port communicating with the supply port at a lower portion,
A surface connecting the lower end portion on the upstream side in the rotation direction of the stirring member of the replenishing port and the lower end portion on the downstream side in the rotation direction of the stirring member of the supply port above the lower end portion is extended. The developing device according to claim 6 , wherein the developing device is located above a free end of the stirring blade. The developer cartridge, accommodating volume of the developer, a developing device according to claim 6 or claim 7, characterized in that less than accommodating volume of the developer in the developer containing portion. A developing device according to any one of claims 1 to 8 ,
A process cartridge comprising: a photosensitive member on which an electrostatic latent image is formed and a developer is supplied from the developing device to form a developer image.

Images